Accompanied by the Duke of Edinburgh, she is scheduled to attend a special service at Chelmsford Cathedral this morning followed by the unveiling of a plaque at Felsted School.

Cathedral spokesman Ruth Collin said the sense of anticipation was growing yesterday as the final preparations were put in place.

“We are all very much looking forward to it,” she said. “The final preparations are being put in place, the seating is out, the flowers arranged – it’s looking great.”

The Bishop of Chelmsford, the Rt Rev Stephen Cottrell, described the visit as the “icing on the cake” for the diocese’s centenary celebrations being held this year.

Assembling a 650-strong guest list, which best represents the diocese’ achievements over the past century, has been a “massive” operation for the cathedral.

Ms Collin explained: “We wanted it to represent the whole range of the work that goes on in the diocese and the cathedral over the past 100 years.”

Clergy, congregation and active members of the community will join the royal visitors for a traditional service, which is to be broadcast on loudspeakers in the churchyard for the public to hear.

The Dean of Chelmsford Nicholas Henshall said: “A lot of people invited are there for their role in the community, whether it is in the voluntary sector, running after-school clubs or activities in hospitals.

“This is not about looking back but looking forward at what the next 100 years will look like.”

The Queen will then visit Felsted School, near Braintree, where she will unveil two commemorative plaques during a special assembly in the Lord Riche Hall, which was opened by Princess Anne in 1989. The visit, which will be “the absolute pinnacle”of the independent school’s 450th anniversary celebrations, forms part of a long heritage of royal visits.

The Queen Mother attended the school’s 400th anniversary celebrations in 1968 and Old Felstedian Sir Marcus Setchell oversaw the delivery of Prince George last year.

Headmaster Dr Mike Walker said: “To have a reigning monarch visit Felsted School will be the absolute pinnacle of our 450th year celebrations.

“The school is busy preparing for this Royal visit and the children are very excited to be part of this special day. I am very proud and fortunate to be headmaster at this time.”